Threading machine



Jan. 27@ 1925. 1,524,427

w. T. GABLE THREADING MAci-IINE Filed March 11. 1924 4 Sheets-Sheet 1 INVENTOR l//TT gable.

ATTO R N EY Jan., 27. l 925.

' W. T. GABLE THREADINGy MACHINE Filed March 11. 1924 4 Sheeis-Sheet 2 INVENTOR QJ l @LW ATTORNEY W. T. GABLE THREADING MACHINE Filed March 11. 1924 4 Sheets-Sheet 3 s s@ 'SP Ml'lillmm AEE' kif

INVENTOR ATTORN EY Ulm il m5.

INVENTOR 4 Sheets-Shea?, 4

W. T. @ABLE THREADING MACHINE Filed Maron 11. 1924 mvg). vr, f

ATTO R N EY Patented Jan. 27, 1925.

UNITED STATES PATENTA oFFicl-z.

WILLIAM 'l'. GABLE, OF BALTIMORE, MARYLAND, ASSIGNOR T0 BETHLEHEM STEEL COMPANY, OF BETHLEHEM, PENNSYLVANIA.

THREADING- MACHINE.

Application led'March 11, 1924. Serial'No. 698403.

My invention relates to thrcadin ma'- vchines of the general type disclosed in the patent todams No. 357,300, dated Feb. 8, 1887, and it has for an object to render machines of this character safer to operate and to increase the productive capacity thereof. More specifically my invention has for an object to provide a threading machine of the character indicated in which the threading die is automatically opened after threading to a predetermined extent.

Referring to the patent to Adams aforesaid, it will he noted that the dies are opened and close-d by means of a collar which is movable longitudinally of the arbor. (.)pening movement is accomplished by means of a pin which comes into engagement wlth a lateral cam on the collar when the latch mechanism of the pin is released. Such latch mechanism is ordinarily released b v a Wedge block carried on a rod movable with the chuck carriage. The pin remains in engagement with the cam groove in the collar until it is again latched` movement thereof for this purpose being effected b v peripheral cam portions on the collar. The dies are closed by backward movement of the chuck carriage, which operates through a rod and a collar to swing a lever, which, in turn, pushes the collar in a direction opposite to 'that in which it has-been moved in order to open the die. lt has happened in some cases that the die would be closed without the pin being disengaged and with the collar resting against the lever. ln such a case, the pin would act on the cam to move the collar and open the die and the movement of the collar would pull the chuck carriage toward the die head. lf a workman should have his hands between the chuck and the die head he might be injured due to this movement particularly if he happens to be working with close clearance between the chuck and the die head as would likely be the case if he was attempting a high rate of production o-r was threading short stock. My invention, therefore, has for an object to provide means for automatically moving the actuating wedge out of the way just as soon as the pin starts to move toward the cam collar with the result that the latch mechanism is free to lock the pin in inactive or disengaged position as soon as it is moved to the latter position by a peripheral cam portion. Regardless of the setting of the c osing lever or the opening Wedge or the close clearance between the chuck and the die head, it is, therefore, impossible to brlng about the dangerous reactive opera tion and consequent movement of the chuck toward the die head in the manner just referred to.

A. further object of my invention is to provide a threading machine for threading nipples or pipes incorporating a reamer mounted on a push rod extending through the arbor the push rod being connected to an automatic tripping device, vwhereby a predetermined and exact length of thread may be provided on pipes or nipples.

Apparatus made in accordance with my invention is illustrated on the accompanying drawings, forming a part of this application, in which:

Figure 1 is a longitudinal sectional view of a threadin machine having my improvements applic thereto;

Figure 2 is a sectional detail view taken along the line H-H of Figure 1;

Figure 3 is a detail view of a reamer and associated parts; t

Figure 4 is a plan view of a machine such as illustrated in Figure 1;

Figure 5 is a sectional view taken along the line V-V of Figure 4 and showing aportion of the reamer push-rod actuated mechanism;

Figures 6,' 7 and 8 are detail views showing parts of the reamer push rod operating nechanism to bring about opening of the les;

Figure 9'is a detail view showing latch mechanism for holding the cam pin ret-racted;

Figure 10 is a sectional view taken along the lineI X-X of Figure 9;

Figure 11 is a sectional View taken along the line XI-XI of Fi re 4; i

Figures 12, 13, 14 and 15 are detail views showing releasing Wedge elements attached to a rod moved by the chuck carriage; Fi 1re 14 being a section along the llne X -XIV of Figure 9, and Figure 15 being a section along the line XV-XV of Figure 14; and

Figure 16 is a detail View of a wedge dcvice t'or attaclnnent to a reamer a'tuatcrl rod as illustrated in Figure 4.

Referring now to the drawings more in detail for a better understanding ot' my invention, I show a threading machine having a pedestal support 10 carrying a bed 11. An arm 12 preferably extends t'rom the pedestal 10 to provide a support 1 3 for a shaft or rod element 14 which is connected to the bed.

A stepped pulley 15, or other suitable speed change device, is mounted on the shaft I4 and l show suchstepped pulley connected to a spur pinion 16 meshing with al gear 17, which is keyed to a hollow arbor 18.

T he hollow arbor is journalled in bearings I9 carried by the bed 11 and it supports at its end opposite to the gear 17 an opening and closing die. at 20, of the general character disclosed in the patent a forcsaid.

A chuck carriage 22 mounted in suitable, gnideways 23 in the bed 1l is movable tothereof is accomplished by upward movement of the pin 35 in the guideway recess 42 formed in a suitable bracket or frame 42 secured to the machine. The pin 35 is normally biased in an upward direction b v a spring 43 arranged between a shoulder 4t on the pin and a shoulder 44 of the recess. The pin 35 is withheld in inactive or disengaged position by means of a slidable latch rod 45 having a latch tongue portion 46 for engagement behind a shoulder 47 on the pin 35. The latch rod is mounted in suitable guide bearings 48 and 49 in the trame 42, a space being provided between the bearings 48 and 49 so that a spring 50 may surround thel rod 45 and abut at one end against the end of the bearing 49, the other end of the spring abutting against a collar 51 secured to the rod 45, whereby tht` rod 45 and the latch portion 46 are biased in a lire tion to engage the latch portion t6 behind the shoulder 47 to hold the rod t5 in retracted position.

As soon as the latch rod 45 is moved to disengage the latch portion 46 from behind the shoulder 47, the pin 35 moves up to enward and away from the die 2t) by any suit-Ngage a lateral cam portion in the manner able means, as by a pinion 24 meshing with a rack 25 on the carriage, the pinion 24 being keyed to a shaft 26 which is operated b v a suitable handwheel 27. chuck or work holder comprising jaws 28 and 29 is movable transversely of the carriage .on a suitable guideway 30 in order to grip or release any suitable work to be threaded.

With the apparatus so far described, work placed between the chuck jaws 28 and 29 and the carriage 25 is moved toward the die until the work initially engages with the cutters, whereupon threads are cut on the work and the work is fed in automatically, the die acting as a nut on the threads being cut.

The die 20 is opened and closed by means of a collar 32 which has peripheral and lateral cam portions 83 and 34. Opening of the dies is accomplished by engagement ol the pin with one of the lateral cam portions 34 resulting in movementot' the collar 32 away from the die and opening ot the latter. The-die may be closed by an almtment 36 carried by a lever 37 having an abutment end 38 in the path ot the collar 39 carried by Aa rod 40 connected to the chuck carriage.

Itl will be' obvious to those skilled in the art that any suitable die device may be used so long as it is of the opening and closing type. I prefer to use a twofpart die head actuated by mechanism of the general character indicated in the' patent aforesaid. As the die per se does not constitute a part of my invention, it is deemed to be unnecessally to refer to it in greater detail.

ssuming that the die is closed, openner just referred to, this movement of the latch rod 45 being brought about by a wedge element 52 of the machine, the wedge element 52 engaging with an abutment bearing surface 53 ou the rod 45.

The wedge element may be carried either by the rod 40 already referred to or by a rod 54 actuated from the rcamer. 'l`he reamer actuating mechanism will now be. described.

Referring to Figures l and 3, it will be seen that I show a reamer 55 having a univel-sal or wobbling connection 56 with respect to a push rod 57, these parts being arranged within the die and within the hollow arbor 18 as shown in Figure l. The outer end of the push rod 57 is connected to a collar 58 which actuates the yoke 5S) of a lever 60 fulcrumed at 61, the other end ot' the lever having a slip-joint connection 62 with respect to a coupling member 63 connected to the rod 54. As illustrated in 1t` igures 6 and 7 the coupling member 63 passes through a bracket bearing 64, the. latter constituting a support for a spring 65 bearing against a collar 66 on the connection 621. The compression of the spring 65 tends to more the push rod and reamer toward the front of the die. The position of the reamer 55 with respect to the die 20 may be' adjusted by setting the collar 58 on the shaft 57, a set screw 58 being provided for this purpose. See Figures 4 and 6.

The Wedge element 52 has a wedging snrearried by a suitable moving part -7 ltltl face 68 for engagement with the abutment portion 53 to release the latch rod 4 5 in the manner aforesaid. The wedge elements for attachment to the reamer actuated rod 54 or to the chuck carriage rod `40`a'resimilar except. that one is the reversefof the other. In Figures 12, 13, 14 and 15, I show a wedge element 52 of a ,design suitable for use on a chuck carria e rod. In Figure 16, I show asimilar w ge element 52' for use on a reamer actuated rod 54, the principal diiference between the wedge elements being that they extend in opposite directions and, therefore, the design must be reversed.

Each 'of the wedge elements 52 and 52 has a pivotal connection 69 with respect to a carrier block 70 having a set screw or equivalent means 71 for adjusting the carrier block to any suitable position along the rods 54 or 40. The Wedge members 52 or 52 are biased about the ivotal connection 69 by means of a spring 2 so that the inclined or wedging surface 68 is normally located in a path to engage the latch rod labutment 53. Biasing movement of the latch member is limited by any suitable stop or-abutment 73 .on the block 70.

I provide for disengagement of the latch member 52 or 52 with respect to the abutment 53 of the latch rod just as soon as the pin 3,5 starts to move toward the cam collar 32, thereby permitting movement of the latch rod 45 toward the pin 35 and engagement of the latch tongue 46 behind the shoulder 47 just as soon -as the pin 35 is moved to inactive or retracted position by a radial or peripheral cam portion 33. Accordingly, I show the lower end of the pin pivotally connected to a lever 74 ful- -crumed at an intermediate point' 75, the

other end of the lever 76 being adapted to overhang a lip 77 on a wedge element 52 or 52. When the wedge element 52 or 52 occupies a position such that the latch rod is released from the pin 35 the end portion 76 will be immediately above the lip 77; and, just as soon as upward movement.

'of the pin 35 commences the lever 74 starts.

to move in such a direction that the end 76 moves the pivoted Wedge member 52 or 52 about its pivot 69 and disengages the inclined or wedged surface 68 from the latch rod abutment 53. This disengaging movement is indicated by dotted lines in Figure 10. .lust as soon as the wedge surface 68 is disengaged, the latch rod 54 is free to move over toward the pin 35, thereby preventing the Wedge surface from coming back into engagement with the abutment 53 when the pin is moved out by a peripheral or radial cam portion 33. As the pin 35 moves up to engage a lateral cam portion 34 to open the die 20, the latch rod 45 is automatically released from the wedging device which brought about the unlatching and the pin 35 is, therefore, automatically latched in retracted position as soon as it is pushed to that position by the next' succeeding radial cam. t

f -Upon reference to Figure 3, it will be noted that thewl'eamer 55 is interior reamer edges 55al to remove interior burrs, etc., with chamfering edges 55h to chamfer off the threadedpipe or nipple end provided with to prevent injury to the threads in handling,

and with, burmshing and abutment edges 55 which burnish thepipe or nip le end and serve as abutment surfaces so t lat the feeding-in motion of the work may move the push rod 57 to operate the latching devices in the manner aforesaid.

My improved threading machine operates as follows: It nipples or pipes are threaded, the lWork is placed in the chuck and fed into the die. Thereafter the work is fed by the thread cutting action of the die. At the same time, the reamer removes interior burrs, chamfers the end, and burnishes the end; and the work acting on the abutment edges 55 of the reamer causes movement of the push rod 57 toward the left, in Figure 1, which results in movement of the lateral rod 54 toward the right, in Figure 4, to bring the wedge 68 fof the wedge element 52 into engagement with the abutment 53 of the latch rod 45, whereupon the latter is moved to disengage its latch tongue from behind the shoulder 47 on the pin 35, permitting the spring 43 to move the cam pin 35 up into engagement with a lateral cam 34 to effect opening of the die. Concurrently with the upward movement of the pin 35, the lever 74 moves the Wedge element 52 out ot'. engagement with t-he abutment 53 so that the latch rod 45 is free to engage behind the shoulder 47 as soon as the pin 35 is depressed b v a radial or peripheral cam 33.

The length of thread on a nipple or pipe muy be regulated by adjusting the collar 58 on the push rod 57 or by adjustment of the block 70 on the rod 54.

If the machine is used to thread bolts or rods, the reamer is removed, and a block 70 having a wedge element 52 (see Figures 12, 13, 14 and 15) is placed on the chuck carriage rod 40. The machine now operates similarly to that disclosed in the patent aforesaid except that, with my machine, the wedge element 52 is released by the upward movement of the pin resulting in immediate locking oi" the latter pin in disengaged or inactive position, thereby avoiding the possibility of having the carriage pulled toward the die head by the pin engaging a lateral cam.

From the foregoing, it will be apparent that I have provided an unlatching mechanism for a cam pin which vis rendered ineffective as soon as the pin starts toward cam-engaging position, thereby making itpossible to latch the cam pin in retracted posltion as soon as the next peripheral cam lll() portion for this purpose comes into engagement therewith thereby making it impos-4 sible, with a machine of this character, by improper or hasty operation to bring about accidental movement of the chuck carriage toward the die. It will also be apparent that, with my improved type of threading machine, threads may be cut on pipes, nipples or rods to predetermined lengths and with great rapidit Havin thus escribed the invention what I c aim as new and desire to secure by Letters Patent is:

1. In a threading machine, the combination of an opening and closing die, means for opening the die including a movable member, latch mechanism for holding the movable member in retracted or disengaged position, an element moved by the machine for disengaging the latch mechanism, and means operated by said member in moving to die-opening position to disengage said element from the latch mechanism.

2. In a threading machine, the combination of an opening and closing die, means to open the die, means to render the lastnamed means effective including a movable element, means for biasing the movable ele ment in one direction, a latch for holding the movable element in inactive position, an abutment on the latch, means carried by a movable part of the machine and cooperating with the abutment to withdraw the latch so that said movable element is free to move in its biased direction, and means actuated b the movable element to move the last-name means away from the abutment, whereby the latch may move toward latchin-g position and en age the movable element as soon as the atter is moved in the other direction to a predetermined extent.

3. In a threading machine, the combination of an opening and closing die, means to open the die, means to render the lastnamed means effective including a pin, a spring for moving the pin in an engaging irection, a shoulder carried by the pin, a latch for engagement with the shoulder to hold the pin disengaged, an' abutment on the latch,`a wedge carried by a movable part of the machine for withdrawing the latch iu order that the spring may move the pin in an engaging direction, and means actuated by the pin in moving in an engaging direction to move the wedge away from the latch abutment, whereby the latch may move toward latching position and engage behind the shoulder of the pin as soon as the latter is moved in a disengaging direction to a predetermined extent.

4. In a threading machine, the combination of an openin and closing die, a reciprocable collar or opening the die, lateral and peripheral cams carried by the collar, a reciprocable pin for engagement with the cams, a spring for moving the piu into en agement with the cams, a shoulder carried y the in, a latch rod for coopera.- tion with the s loulder to hold the pin disengaged from the cams, an abutment carried by the latch rod, means for biasing the latch rod toward the pin, a member movable incident to the operation ofthe machine, a

wedge pivoted to said member and adapted to engage the latch rod abutment to withdraw the latch rod from engagement with the pin shoulder, and means actuated by the pin for disengaging the wedge from the latch rod abutment, whereby the latch rod may move in a latching direction and engage the abutment of the pin as soon as the latter is moved by a peripheral cam to an extent sutlicient for the pin shoulder to pass beyond the latch rod in one direction.

5. In a threading machine, the combination of an opening and closing die, means to open the die including a reciprocable cam collar having lateral and peripheral cam portions, a reciprocable pin for engagement with the lateral cam portions to secure movement of the collar in one direction and engaged by the peripheral cam portions to be moved to inactive position, a spring for moving the pin into cam-engaging position, a shoulder carried by the pin, a latch rod for engagement with the shoulder to hold the pin in inactive position, a spring for moving the latch rod into engagement with the pin shoulder, an abutment carried by the latch rod, a shaft which moves longitudinally incident to operation of the machine, a wedge element pivotally mounted with respect to said shaft and moved by the latter into engagement with the latch rod abutment to disengage the latch rod from the pin, and means actuated by movement of the pin in a cam-engaging direction to move the wedge about its pivot away from the latch rod abutment, whereby the latch rod is moved immediately by its spring toward the in and engages behind the shoulder of the atter as soon as the pin is moved in a disengaging direction to a sufiicient extent by one of the peripheral cams.

(i. In a threading machine.' the combination of an opening and closing die` means to open the die including a rceiprocable collar, lateral and peripheral cam portions on the collar, a slidable pin for engagement with a lateral cam portion to secure movement of the collar in a direction to open the die and for engagement with a peripheral cam portion in order that the pin may be moved to inactive position, a spring cooperating with the pin to move it in a cam-engaging direction, a shoulder carried by the pin, a latch member for engagement with the shoulder to hold the pin in disengaging position, a spring for holdin the latch member in engagement with t e shoulder,

an abutment carried by the latch member a member which moves longitudinall o the machine incident to the operation o the latter, a wedge pivoted to isaid member, means for biasing the wedge to such a osition as to engage with the latch member abutment, a lever fulcrumed at al1-.intermediate point and having one end connected to the pin and the other end adapted to engage with the wedge, whereby, upon move, ment of the pin in a cam-engaging direction, the lever is o rated to withdraw the wedge from the latc member abutment whereupon the latch member moves under the influence of its spring toward the pin and engages behind the abutment of the latter as soon as the pin is moved to a sufficient extent by a peripheral cam. 1

7. In a threading machine, the combination of an opening and closing die, means to open the die including a reciprocable collar havin peripheral and lateral cam ortions, a pin movable toward and away rom i the collar, a spring for moving the pin toward the collar, said pin engaging a lateral cam portion to move the collar in a direction to openthe die and being engaged by peripheral cam portion in order that it may be moved away from the collar, a shoulder on the pin, a latch member for engagement behind the shoulder to hold the pin out of engagement with the cam portions, a spring cooperating with thel latch member to move the latter in a shoulderengaging direction, an abutment carried by the latch member, a member movable longitudinally of the machine incident t0 the operation of the latter, a wedge pivotally mounted with respect to the latter member and adapted to engage with the abutment of the latch member to, withdraw the latter from the shoulder, means for biasing the wedge to a position such that it may engage the latch member abutment, a lateral shoulder carried by the wedge, a lever ful crumed at an intermediate point and having one end connected to the rod and having its other end adapted to be arranged over theshoulder of the wedge when the latter is moved into ition to engage with 'the latch member albistment, whereby, when the pin moves toward the collar the lever engages the wedge shoulder to withdraw the wedrre from the latch member abutment permittlng the latch member to move toward the pin so that it may engage behind the shoulder of the latter when the pin is moved away from the collar by a peripheral cam.

8. In a pipe or nipple threading machine, the combination of a hollow arbor, an o ening and closing die carried by the ar or, a work holder, a reamer in the die and having abutment surfaces, a push rod connected to the reamer and adapted to be moved by the work abutting the abutment surfaces of the latter, a collar movable on the arbor to open the die, lateral and peripheral cam portions on the collar, a pin .movable into ,engagement with a lateral cam portion to open the die and'bei movable to an inactive position by a perip eral cam portion, a spring for moving the pin toward the collar; latch mechanism for holding the in in disengaged position, means operated Jy the push rod for disengaging the latch mechanism from the pin whereupon the latter moves into engagement with a lateral cam portion to open the die, means operated by the pin during its cam-egaging movement to disengage said push-rod operated mechanism from the latch mechanism to permit the latter to lock the in in disengaged position vwhen such pm is lmoved away from the collar to a suiiicient extent by a peripheral cam portion, and means rendered effective by backward movement of the work holder to close the die.

9. In a pipe or nipple threading machine, the combination of a hollow arbor, an opening and closig die carried by the arbor, a work holder, a reamer in the die and having abutment surfaces, a push rod connected to the reamer and adapted to be moved by the work abutting the abutment surfaces of the latter, a collar movable on the arbor to open the die, lateral and peripheral cam portions on the collar, a pin movable into engagement with a lateral cam portion to open the die and being movable to an inactive position by a peripheral cam portion, a spring for moving the pin toward the collar, a shoulder on the pin, a longitudinally-movable latching member for engagement behind the shoulder to hold the pin retracted, aA spring for moving the member to engage behind the shoulder, an abutment on said member, a rod movable by said push rod, a wedge member pivotally mounted with respect to the last-named rod and adapted to engage said abutment, means for biasing the wedge member to the abutment-engaging path, and means operated by the pin in moving toward'the cam collar for disengaging said wedge element from the abutment, whereby said member immediately moves toward the pin and engages behind the shoulder of the latter as soon as such pin is moved to inactive position by a peripheral cam portion.

10. In a pipe or nipple threading machine, the combination of a hollow arbor, an opening and closing die carried by the arbor, a reamer in the dieand having abutment surfaces, a push rod in the arbor and connected to the reamer and adapted to be moved by the work abutting the abutment surfaces of the latter, a collar movable on the arbor to open the die, lateral and peripheral cam portions on the collar, a pin movable into engagement with a lateral cam portion to open the die and bein movable to an inactive position by aperip ieral cam portion, a sprmg for moving the pin toward the collar, a shoulder on the 1nn, a longitudinally movable latching member for engagement behind the shoulder to hold the in retracted, a spring for moving the mem er to engage behind the. shoulder, an abutment on said member, a lever pivotally connected at one end to the push rod and fulcrumed at an intermediate point, a lateral rod pivotally connected to the other end of the lever, an adjustably mounted block on the lateral rod, a wedge member pivoted to the block and adapted to engage said abutment for withdrawing the latching member from the shoulder, means for biasing the wedge member to the abutment-engaging path, and means operated by the pin in'moving toward the cam collar for disengaging said wedge element from the abutment, whereby said member immediately moves toward the pin and engages behind the shoulder of the latter as soon as such in is moved in inactive position by a peripiieral cam portion.

11. In a pipe or nipple threading machine, the combination ot' a hollow arbor, an opening and closing die carried by the arbor, a reamer in the die and having abutment surfaces, a push rod in the arbor and connected to the reamer and adapted to be moved by the work abutting the abutment surfaces of the latter, an adjustable collar on the push rod, a collar movable. on the arborto open the die, lateral and peripheral cam portions on the collar, a pin movable into engagement with a lateral cam portion to open the die and being movable to aninactive position by Aa perlpheral cam portion, a sprmg for moving the pin toward the collar, a shoulder on the pin, a longitudinally movable latching member for engagement behind the shoulder to hold the pin retracted, a spring for moving the member to engage behind the shoulder, an abutment on said member, a lever pivotally connected at one end to the adjustable pushrod collar and fulcrumed at an intermediate point, a lateral rod pivotally connected to the other end of the lever, an adjustably mounted block on the lateral rod` a wedge member pivoted to the block and adapted to engage said abutment for withdrawing the latching member from the shoulder, means for biasing the Wedge member to the abutment-engaging path, and means operated by the pin in moving toward the cam collar for disengaging said wedge element from the abutment, whereby said member immediately moves toward the pin and engages behind the shoulder' of the latter as soon as such pin is moved in inactive position by a peripheral cam portion.

12. In a pipe or nipple threading machine, the combination of a hollow arbor, an opening and closing die carried by the arbor, a work holder, a reamer in the die and adapted to be moved by the work abuttin the abutment surfaces of the latter, a pus 1 rod in the arbor and connected to the reamer, a collar movable on the arbor to open the die, lateral and peripheral cam portions on the collar, a )in movable into engagement with a laterai cam portion to open t 1e die and bein r movable to an inactive p0- sition by a peri p xeral cam portion, a spring for moving the pin toward the collar, a shoulder on the pin, a longitudinall -movable latehing member for engagement hind the shoulder to hold the pin retracted a spring for moving the member to engage hind the shoulder, an abutment on said member, a rod movable by said push rod, an adjustably mounted block on the rod, a wedge member pivoted to the block and having a laterally projecting,r lip, said wedge member adapted to engage the abutment to withdraw the latehing member from the shoulder, means for biasing the wedge member to the abutment-engaging path, and a pivotally mounteddcver engaging the in and adapted to contact with said lip w ien the pin moves toward the cam collar, whereby the wedge member is disengaged from the latching member abutment. and the latter member moves immediately toward the )in and engages behind the shoulder of the iatter as soon as such pin is moved to inactive position b v a peripheral cam portion.

13. In a threading machine, the combination of a hollow arbor, an opening and closing die carried by the arbor, a work holder, a carriage for the work holder, a collar movable on the arbor for opening and closing the die, peripheral and lateral cam portions on the collar,-a piu movable into engagement with a lateral cam portion to open the die and being movable to inactive position by a peripheral cam portion, means for biasing the pin toward the collar, latch mechanism for holding the pin in disengaged position, push rod mechanism e tending through the arbor and into the die to an extent determined by the desired length of thread and adapted to be moved by the work, means operated by the push rod to release the latch mechanism, whereupon the pin moves to engage a lateral cam portion to open the die` means operated by upward movement of the pin to disengage thepushrod operated means from the latch mechanism, whereby the pin lnay be latched in inactive position when it is moved out by a peripheral cam portion, and means operated by backward motion of the carriage to move the collar to close the die.

In testimony whereof I hereunto aix my signature this 27th day of Februa 1924.

WILLIAM T. GA LE.

llo 

